It is presumed in this article, that you have some version of AutoCAD and M-Color installed and that you install a new 2018 AutoCAD version
and want to preview or print the linetype plot drawings from M-Color like they were in previous AutoCAD versions.
Impacted Impacted Products and Versions
AutoCAD Version: 2018. M-Color version 9.9
M-Color prints have the majority of the linetype, in reference file as a continuous line. Theyhad been dotted lines in previous AutoCAD version.
Cause and Reason
AutoCad 2018 forces the continuous linetype even though it's not used at all in the drawing or in the attached XREF.
However, by replacing the liteypes with index 0 and 1 (ByLayer and ByBlock) with wanted linetype ID in WriteTailerLinetypesLinetype (FormatMCL.cpp)
all the lines in the drawing uses the given linetype. This indicates that these linetypes (from master document) are forced for XREFs lines.
Solution / Workaround
This issue is fixed in M-Color 9.9.566.0 and higher